Add support for gzipped json files (#2435)

.gitignore

@@ -35,6 +35,7 @@
 .idea/androidTestResultsUserPreferences.xml
 .idea/appInsightsSettings.xml
 .idea/migrations.xml
+.idea/deploymentTargetSelector.xml
 
 # Gradle
 .idea/**/gradle.xml

lottie/src/main/java/com/airbnb/lottie/LottieCompositionFactory.java

@@ -11,6 +11,7 @@
 import android.graphics.BitmapFactory;
 import android.graphics.Typeface;
 import android.util.Base64;
+import android.util.Log;
 
 import androidx.annotation.Nullable;
 import androidx.annotation.RawRes;
@@ -41,7 +42,7 @@
 import java.util.Set;
 import java.util.concurrent.Callable;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.zip.GZIPInputStream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
@@ -57,6 +58,7 @@
  */
 @SuppressWarnings({"WeakerAccess", "unused", "NullAway"})
 public class LottieCompositionFactory {
+
   /**
    * Keep a map of cache keys to in-progress tasks and return them for new requests.
    * Without this, simultaneous requests to parse a composition will trigger multiple parallel
@@ -69,7 +71,8 @@ public class LottieCompositionFactory {
    * reference magic bytes for zip compressed files.
    * useful to determine if an InputStream is a zip file or not
    */
-  private static final byte[] MAGIC = new byte[]{0x50, 0x4b, 0x03, 0x04};
+  private static final byte[] ZIP_MAGIC = new byte[]{0x50, 0x4b, 0x03, 0x04};
+  private static final byte[] GZIP_MAGIC = new byte[]{0x1f, (byte) 0x8b, 0x08};
 
 
   private LottieCompositionFactory() {
@@ -222,10 +225,13 @@ public static LottieResult<LottieComposition> fromAssetSync(Context context, Str
       return new LottieResult<>(cachedComposition);
     }
     try {
-      if (fileName.endsWith(".zip") || fileName.endsWith(".lottie")) {
-        return fromZipStreamSync(context, new ZipInputStream(context.getAssets().open(fileName)), cacheKey);
+      BufferedSource source = Okio.buffer(source(context.getAssets().open(fileName)));
+      if (isZipCompressed(source)) {
+        return fromZipStreamSync(context, new ZipInputStream(source.inputStream()), cacheKey);
+      } else if (isGzipCompressed(source)) {
+        return fromJsonInputStreamSync(new GZIPInputStream(source.inputStream()), cacheKey);
       }
-      return fromJsonInputStreamSync(context.getAssets().open(fileName), cacheKey);
+      return fromJsonInputStreamSync(source.inputStream(), cacheKey);
     } catch (IOException e) {
       return new LottieResult<>(e);
     }
@@ -298,6 +304,13 @@ public static LottieResult<LottieComposition> fromRawResSync(Context context, @R
       BufferedSource source = Okio.buffer(source(context.getResources().openRawResource(rawRes)));
       if (isZipCompressed(source)) {
         return fromZipStreamSync(context, new ZipInputStream(source.inputStream()), cacheKey);
+      } else if (isGzipCompressed(source)) {
+        try {
+          return fromJsonInputStreamSync(new GZIPInputStream(source.inputStream()), cacheKey);
+        } catch (IOException e) {
+          // This shouldn't happen because we check the header for magic bytes.
+          return new LottieResult<>(e);
+        }
       }
       return fromJsonInputStreamSync(source.inputStream(), cacheKey);
     } catch (Resources.NotFoundException e) {
@@ -402,7 +415,8 @@ public static LottieResult<LottieComposition> fromJsonReaderSync(com.airbnb.lott
   }
 
   @WorkerThread
-  public static LottieResult<LottieComposition> fromJsonReaderSync(com.airbnb.lottie.parser.moshi.JsonReader reader, @Nullable String cacheKey, boolean close) {
+  public static LottieResult<LottieComposition> fromJsonReaderSync(com.airbnb.lottie.parser.moshi.JsonReader reader, @Nullable String cacheKey,
+      boolean close) {
     return fromJsonReaderSyncInternal(reader, cacheKey, close);
   }
 
@@ -641,9 +655,20 @@ private static LottieResult<LottieComposition> fromZipStreamSyncInternal(Context
    * Check if a given InputStream points to a .zip compressed file
    */
   private static Boolean isZipCompressed(BufferedSource inputSource) {
+    return matchesMagicBytes(inputSource, ZIP_MAGIC);
+  }
+
+  /**
+   * Check if a given InputStream points to a .gzip compressed file
+   */
+  private static Boolean isGzipCompressed(BufferedSource inputSource) {
+    return matchesMagicBytes(inputSource, GZIP_MAGIC);
+  }
+
+  private static Boolean matchesMagicBytes(BufferedSource inputSource, byte[] magic) {
     try {
       BufferedSource peek = inputSource.peek();
-      for (byte b : MAGIC) {
+      for (byte b : magic) {
         if (peek.readByte() != b) {
           return false;
         }

snapshot-tests/src/androidTest/java/com/airbnb/lottie/snapshots/tests/AssetsTestCase.kt

@@ -31,7 +31,7 @@ class AssetsTestCase : SnapshotTestCase {
                 listAssets(assets, pathWithPrefix)
                 return@forEach
             }
-            if (!animation.endsWith(".json") && !animation.endsWith(".zip")) return@forEach
+            if (!animation.endsWith(".json") && !animation.endsWith(".zip") && !animation.endsWith(".tgs")) return@forEach
             assets += pathWithPrefix
         }
         return assets
@@ -47,4 +47,4 @@ class AssetsTestCase : SnapshotTestCase {
             send(asset to composition)
         }
     }
-}
+}